1. Field of the Invention
The present invention relates generally to a control system for an automotive suspension system for adjusting suspension characteristics depending upon vehicle driving condition. More specifically, the invention relates to a suspension control system which requires lessor arithmetic processing of suspension control parameters and thus can enhance response characteristics.
2. Description of the Background Art
Japanese Patent First (unexamined) Publication (Tokkai) Showa 62-181908 discloses one example of a suspension control system. The suspension control system includes an acceleration sensor for monitoring vertical acceleration to be generated in response to bounding and rebounding strokes of vertical vibration. A variable damping force shock absorber is provided in a suspension system and is associated with the suspension control system for adjusting damping characteristics. The control system monitors vehicular driving condition for deriving optimal damping characteristics depending thereon.
In such conventional prior art, a vertical acceleration dependent control parameter is derived on the basis of the monitored vertical acceleration by means of the vertical acceleration sensor. The acceleration dependent control parameter is compared with a predetermined threshold value for controlling the damping characteristics of the variable damping force shock absorber based on the result of comparison. In order to perform the arithmetic operation, the control system is required to have a capability for differentiation and integration of the data to be processed. Therefore, the microprocessor forming the core of the control system becomes complicated and requires a high cost. Furthermore, a larger system necessarily requires greater processing time for lowering of the response characteristics.